From 0c40c18e98baca899b1b70c8c138a5320ccacda0 Mon Sep 17 00:00:00 2001
From: Mine Starks <mineyalc@microsoft.com>
Date: Mon, 10 Jul 2017 12:49:29 -0700
Subject: [PATCH] Applying edits in Fourslash can cause caret to move off-range

---
 src/harness/fourslash.ts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/harness/fourslash.ts b/src/harness/fourslash.ts
index 434a3981461..04fc21e60e0 100644
--- a/src/harness/fourslash.ts
+++ b/src/harness/fourslash.ts
@@ -1797,6 +1797,10 @@ namespace FourSlash {
                 // this.languageService.getScriptLexicalStructure(fileName);
             }
 
+            if (this.currentCaretPosition < 0) {
+                this.currentCaretPosition = 0;
+            }
+
             if (isFormattingEdit) {
                 const newContent = this.getFileContent(fileName);